T Mobile and Asurion Was charged for insurance I never requested and continued to be charged for it after being told I had successfully canceled it both by Asurion and TMobile Internet

In 2010 I needed a replacement phone.  I went to the T Mobile store in Brooklyn, and was given a new phone, which I was told was free, as part of my plan.  About a week later, I received an envelope in the mail from Asurion telling me that I had an insurance policy on my phone, which I never requested. I was paying appx. $10.00 per month for this policy.  I called Asurion to cancel this policy and was told that I had successfully cancelled it.  In 2011, I noticed my bills were about $10 more than they should be.  I called T Mobile to go over the charges, and was not told that I was still paying for insurance.  About a month ago, I called again and this time I was told I was still paying for the insurance (two years later).  I told the TMobile representative that I had cancelled the policy in 2010 by callin Asurion, but was informed that I could not cancel the insurance directly...that it can only be cancelled through TMobile.  I was not told this when I cancelled the policy with Asurion.  The person at TMobile said that she cancelled the insurance, and then told me that I would receive a call from a supervisor.  I never received a call.  Today, I called again in hopes of speaking to a supervisor and was informed that I was still paying for the insurance.  I was again, not allowed to speak to a supervisor.  This time, they say that they have cancelled the insurance...though I have been paying for it over two years.  I have been told several times that it has been cancelled only to find out I am still paying...so I have no confirmation that the policy has indeed been cancelled this time.